advances in the research of aquatic environment volume 2

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  • Environmental Earth Sciences Series Editor: James W. LaMoreaux For further volumes: http://www.springer.com/series/8394
  • Nicolaos Lambrakis George Stournaras Konstantina Katsanou Editors Advances in the Research of Aquatic Environment Volume 2 123
  • Editors Prof. Dr. Nicolaos Lambrakis University of Patras Department of Geology Laboratory of Hydrogeology Patras Greece [email protected] Prof. Dr. George Stournaras University of Athens Department of Geology and Geoenvironment Athens Greece [email protected] Konstantina Katsanou University of Patras Department of Geology Laboratory of Hydrogeology Patras Greece [email protected] ISBN 978-3-642-24075-1 e-ISBN 978-3-642-24076-8 DOI 10.1007/978-3-642-24076-8 Springer Heidelberg Dordrecht London New York Library of Congress Control Number: 2011936434 Springer-Verlag Berlin Heidelberg 2011 This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilm or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer. Violations are liable to prosecution under the German Copyright Law. The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Cover design: deblik, Berlin Printed on acid-free paper Springer is part of Springer Science+Business Media (www.springer.com)
  • v Preface These two volumes contain the proceedings of the 9th International Congress of Hydrogeology and the 4th MEM Workshop on Fissured Rocks Hydrology, organ- ized by the Hellenic Committee of Hydrogeology in collaboration with the Cyprus Association of Geologists and Mining Engineers. The number of the manuscripts submitted to the Organizing Committee through- out 15 countries all over the world reflects the rapidly increasing interest that Hy- drology gains nowadays worldwide. The papers cover more or less all fields, such as mathematical modeling, statistical, hydro-chemical methods, etc., focusing on the environmental aspect. Aquatic environment, the main topic of the Congress, as it is shown by the title of the Proceedings Advances in the research of aquatic environment is covered by articles mostly dealing with ecological impacts versus water requirements, climate change implications on groundwater, anthropogenic impacts on the groundwater quality, groundwater vulnerability, and more. Both volumes follow the general structure of the Congress topics. Moreover the keynote lectures are also included. On behalf of the International Scientific Committee I would like to take this op- portunity to thank all the authors for their contributions, as well as all participants for their cooperation, which made this Congress possible. Additionally, I would like to express my gratitude to the staff of Springer and especially Christian Witschel and Agata Oelschlaeger for their hard work, patience and support. Last but not least, I would like to thank my wife Aggeliki and my children Athina and Ioannis for their patience and love. Prof. Nicolaos Lambrakis President of the Organizing Committee University of Patras Laboratory of Hydrogeology Rio Patras, Greece
  • vii Address of the Hellenic Committee of Hydrogeology The Hellenic Chapter of IAH proudly presents the Proceedings of its 9th Interna- tional Hydrogeological Congress, integrated in the frame, established during the last decade, characterized by internationalization and an opening to adjacent scien- tific fields. This is the result of continuous and painstaking efforts of all the mem- bers of the Hellenic Committee of Hydrogeology and of our foreign colleagues who attended our congresses and contributed by their papers and key notes and chiefly by their presence. The discussed Congress is characterized by several features and particularities. First of all, it is the first time that our Congress deserts the big cities for the Hel- lenic periphery cities as it is Kalavrita, the city which entertains our present meet- ing. Second, the international economic crisis affected both the attendance of delegates and the sponsoring of the event. Despite these difficulties the partici- pants and the sponsors presence exceeded the expected range. Moreover, the fo- cusing given to our congress subject matter, the management of the aquatic envi- ronment, covers a very important topical and seasonable existing universal problem, especially under the effect of the climatic change. Finally, the associa- tion with our new publisher, Springer is something that improves the level of the Congress in the field of the presentation quality and of the international diffusion of the proceedings as well. The IAH Hellenic National Chapter wishes to express its gratitude to the Organiz- ing Committee and its Chairman, Prof. N. Lambrakis for what they have done, the Sponsors of the event in such a difficult period, the local authorities of the city and the region of Kalavrita, the authors of the papers and key notes, and the partici- pants for their important presence in the congress. For the Administration Council The President Prof. George Stournaras
  • ix Acknowledgements The 9th International Hydrogeological Congress of Greece would not have been pos- sible to be carried out without the active engagement of many persons and the finan- cial support of Institutions and Organizations. I would like to express my gratitude to all of them. Moreover, I would like to thank in particular Mr Dimitris Dalianis for his perfect work in the construction and maintenance of the Congress website. I would also like to acknowledge Mrs Konstantina Katsanou, Panagoula Kriempardi and Katerina Karli, for their valuable contribution during the organization. Sponsors BANK OF GREECE M.E.W.S OF PATRAS UNIVERSITY OF PATRAS MARIOLOPOULOS KANAGINIS FOUNDATION AGRICULTURAL UNIVERSITY OF ATHENS DR C.J.VAMVACAS LTD HIGH-TECH PRODUCTS- CONSULTANTS GEOTECHNICAL CHAMBER OF GREECE KLEOPATRA GOUVA CHEMICALS PARTNERSHIP LAZARIDIS
  • xi Organizing Committee The 9th International Hydrogeological Congress and the 4th MEM Workshop of Fissured Rocks Hydrology of the Hellenic Committee of Hydrogeology in col- laboration with the Geological Society of Greece and the Cyprus Association of Geologists and Mining Engineers, was organized by the Laboratory of Hydro- geology, Department of Geology, University of Patras, with the cooperation of colleagues from several universities and authorities. The Organizing Committee consists by the following members: President: Nikolaos Lambrakis, University of Patras, Laboratory of Hydrogeology Vice President: Evangelos Nikolaou, IGME Greece General Secretary: Anastasia Pyrgaki, Region of Western Greece Executive Secretary: Konstantina Katsanou, University of Patras, Laboratory of Hydrogeology Koumoutsou Eleni Chelmos Vouraikos Geopark Treasurer: Eleni Zagana, University of Patras, Laboratory of Hydrogeology Members: Christos Petalas, Department of Environmental Engineering, Democritus Univer- sity of Thrace Constantinos Constantinou, Geological Survey of Cyprus Grigorios Krestenitis, Region of Western Greece Markos Sklivaniotis, M.E.W.S.P of Patras Georgios Soulios, Aristotle University of Thessaloniki, Department of Geology Georgios Stamatis, Agricultural University of Athens, Laboratory of Mineralogy- Geology Georgios Stournaras, Faculty of Geology and Geoenvironment, University of Ath- ens Leonardos Tiniakos Region of Western Greece
  • xiii Scientific Committee Mohamed Aboufirass (N. Africa) Argyro Livaniou (Greece) Ian Acworth (Australia) Manuel Jos Margues (Portugal) Apostolos Alexopoulos (Greece) Paulos Marinos (Greece) Bartolome Andreo (Spain) Henrik Marszalek (Poland) Athanasios Argyriou (Greece) Boris Mijatovic (Serbia) Alicia Aureli (Italy) Jacque Mudry (France) Giovanni Barrocu (Italy) Konstantinos Nikolakopoulos (Greece) Konstantinos Chalikakis (France) Euagelos Nikolaou (Greece) Antonio Chambel (Portugal) Andreas Panagopoulos (Greece) Massimo Civita (Italy) George Panagopoulos (Greece) John Diamantis (Greece) George Papatheodorou (Greece) Alexandros Dimitrakopoulos (Greece) Didier Pennequin (France) George Dimopoulos (Greece) Christos Petalas (Greece) Romeo Eftimi (Albania) Fotios Pliakas (Greece) Christophe Emblanch (France) Maurizio Polemio (Italy) Dolores Maria Fidelibus (Italy) Antonio Pulido Bosch (Spain) Bjrn Frengstad (Norway) Dimitris Rozos (Greece) Michael Fytikas (Greece) Kim Rudolph-Lund (Norway) Michael Galabov (Bulgary) Nikolaos Sambatakakis (Greece) Jacques Ganoulis (Greece) Allen Shapiro (USA) Panagiotis Giannopoulos (Greece) George Soulios (Greece) Vasileios Kaleris (Greece) George Stamatis (Greece) George Kallergis (Greece) George Stournaras (Greece) George Koukis (Greece) Luigi Tulipano (Italy) John Koumantakis (Greece) Peter Udluft (Germany) Andre Kranjc (Slovenia) Sotirios Varnavas (Greece) Jiri Krasny (Czech Republic) Konstantinos Voudouris (Greece) Ioannis Kyrousis (Greece) Qin Xiaoqun (China) Patrik Lachassagne (France) Eleni Zagana (Greece) Nikolaos Lambrakis (Greece) Hans Zojer (Austria) John Leontiadis (Greece) Nikolaos Zouridakis (Greece) Michael Leotsinidis (Greece)
  • xv Contents Volume 1 Water bodies and ecosystems Groundwater in integrated environmental consideration................................... 3 G. Stournaras Ecological requirements (Habitats Directive) versus water requirements (Water Framework Directive) in wetland ecosystems in Spain......................... 21 A. de la Hera, J.M. Forns, M. Bernus, J.J. Durn Ecological impacts due to hydraulic technical projects to ecosystems near Natura 2000 network ................................................................................. 29 Th.M. Koutsos, G.C. Dimopoulos, A.P. Mamolos Climate change Approaches for increasing and protecting fresh water resources in light of climate change................................................................................................... 41 G.A. Kallergis Estimation of hourly groundwater evapotranspiration using diurnal water table fluctuations ............................................................................................... 51 L.H. Yin, G.C. Hou, D.G. Wen, H.B. Li, J.T. Huang, J.Q. Dong, E.Y. Zhang, Y. Li Estimation of precipitation change over Greece during the 21st century, using RCM simulations..................................................................................... 57 J. Kapsomenakis, P.T. Nastos, C. Douvis, K. Eleftheratos, C.C. Zerefos Trends and variability of precipitation within the Mediterranean region, based on Global Precipitation Climatology Project (GPCP) and ground based datasets .................................................................................................... 67 P.T. Nastos Climatic influence on Lake Stymphalia during the last 15 000 years ............... 75 I. Unkel, C. Heymann, O. Nelle, E. Zagana Climate change impact on the Almiros brackish karst spring at Heraklion Crete Greece...................................................................................................... 83 A.I. Maramathas, I. Gialamas
  • xvi Contents Climate Change Implications on Groundwater in Hellenic Region .................. 91 G. Stournaras, G. Yoxas, Emm. Vassilakis, P.T. Nastos Climatic modelling and groundwater recharge affecting future water demands in Zakynthos Island, Ionian Sea, Greece............................................ 99 P. Megalovasilis, A. Kalimeris, D. Founda, C. Giannakopoulos Hydrology Using spectral analysis for missing values treatment in long-term, daily sampled rainfall time series...................................................................... 111 E. Fakiris, D. Zoura, K. Katsanou, P. Kriempardi, N. Lambrakis, G. Papatheodorou Suitability of DSM derived from remote sensing data for hydrological analysis with reference to the topographic maps of 1/50000............................. 121 K. Nikolakopoulos, E. Gioti A GIS method for rapid flood hazard assessment in ungauded basins using the ArcHydro model and the Time-Area method .................................... 129 M. Diakakis Flood hazard evaluation in small catchments based on quantitative geomorphology and GIS modeling: The case of Diakoniaris torrent (W. Peloponnese, Greece)................................................................................. 137 E. Karymbalis, Ch. Chalkias, M. Ferentinou, A. Maistrali Preliminary flood hazard and risk assessment in Western Athens metropolitan area............................................................................................... 147 M. Diakakis, M. Foumelis, L. Gouliotis, E. Lekkas Effects on flood hazard in Marathon plain from the 2009 wildfire in Attica, Greece ............................................................................................................... 155 M. Diakakis Flash flood event of Potamoula, Greece: Hydrology, geomorphic effects and damage characteristics................................................................................ 163 M. Diakakis, E. Andreadakis, I. Fountoulis Hydrograph analysis of Inountas River Basin (Lakonia, Greece)..................... 171 C. Gamvroudis, N. Karalemas, V. Papadoulakis, O. Tzoraki, N.P. Nikolaidis
  • Contents xvii Hydrologic modelling of a complex hydrogeologic basin: Evrotas River Basin........................................................................................... 179 O. Tzoraki, V. Papadoulakis, A. Christodoulou, E. Vozinaki, N. Karalemas, C. Gamvroudis, N.P. Nikolaidis Evolution tendency of the coastline of Almyros basin (Eastern Thessaly, Greece)................................................................................ 187 G. Chouliaras, A. Pavlopoulos An insight to the fluvial characteristics of the Mediterranean and Black Sea watersheds ................................................................................. 191 S.E. Poulos Flooding in Peloponnese, Greece: a contribution to flood hazard assessment ......................................................................................................... 199 M. Diakakis, G. Deligiannakis, S. Mavroulis Estimation of sedimentation to the torrential sedimentation fan of the Dadia stream with the use of the TopRunDF and the GIS models .............................. 207 A. Vasiliou, F. Maris, G. Varsami Continuous media Hydrogeology Modeling of groundwater level fluctuations in agricultural monitoring sites.... 217 V. Vircavs, V. Jansons, A. Veinbergs, K. Abramenko, Z. Dimanta, I. Anisimova, D. Lauva, A. Liepa Groundwater level monitoring and modelling in Glafkos coastal aquifer......... 225 A. Ziogas, V. Kaleris A data-driven model of the dynamic response to rainfall of a shallow porous aquifer of south Basilicata - Italy........................................................... 233 A. Doglioni, A. Galeandro, V. Simeone Evaluating three different model setups in the MIKE 11 NAM model............. 241 Ch. Doulgeris, P. Georgiou, D. Papadimos, D. Papamichail Potential solutions in prevention of saltwater intrusion: a modelling approach ........................................................................................ 251 A. Khomine, Sz. Jnos, K. Balzs Geophysical research of groundwater degradation at the eastern Nestos River Delta, NE Greece..................................................................................... 259 I. Gkiougkis, T. Tzevelekis, F. Pliakas, I. Diamantis, A. Pechtelidis
  • xviii Contents Piezometric conditions in Pieria basin, Kavala Prefecture, Macedonia, Greece............................................................................................ 267 T. Kaklis, G. Soulios, G. Dimopoulos, I. Diamantis Water Balance and temporal changes of the surface water quality in Xynias basin (SW Thessaly) ......................................................................... 275 N. Charizopoulos, G. Stamatis, A. Psilovikos Hydraulic connection between the river and the phreatic aquifer and analysis of the piezometric surface in the plain west of Mavrovouni, Laconia, Greece................................................................................................. 283 N. Karalemas Groundwater recharge using a Soil Aquifer Treatment (SAT) system in NE Greece..................................................................................................... 291 F. Pliakas, A. Kallioras, I. Diamantis, M. Stergiou Enhancing Protection of Dar es Salaam Quaternary Aquifer: Groundwater Recharge Assessment.................................................................. 299 Y. Mtoni, I.C. Mjemah, M. Van Camp, K. Walraevens Analysis of surface and ground water exchange in two different watersheds... 307 M. Bogdani-Ndini Evaluation of multivariate statistical methods for the identification of groundwater facies, in a multilayered coastal aquifer................................... 315 E. Galazoulas, C. Petalas, V. Tsihrintzis Delimitation of the salinity zone of groundwater in the front between the municipalities of Moschato and Glyfada of the prefecture of Attica........... 323 Ch. Mpitzileki, I. Koumantakis, E. Vasileiou, K. Markantonis Hydrogeological conditions of the upper part of Gallikos river basin............... 331 C. Mattas, G. Soulios A methodological approach for the selection of groundwater monitoring points: application in typical Greek basins........................................................ 339 A. Panagopoulos, Y. Vrouhakis, S. Stathaki Stochastic Modeling of Plume Evolution and Monitoring into Heterogeneous Aquifers............................................................................. 349 K. Papapetridis, E.K. Paleologos
  • Contents xix Hydrogeological conditions of the lower reaches of Aliakmonas and Loudias rivers aquifer system, Region of Central Macedonia, Northern Greece ................................................................................................ 357 N. Veranis, A. Chrysafi, K. Makrovasili Estimation of Hydrological Balance of Rafinas Megalo Rema basin (Eastern Attica) and diachronic change of the surface water quality characteristics.................................................................................................... 365 P. Champidi, G. Stamatis, K. Parpodis, D. Kyriazis Karst Hydrogeology Dynamic Characteristics of Soil Moisture in Aeration Zones under Different Land Uses in Peak Forest Plain Region................................... 375 F. Lan, W. Lao, K. Wu Situation and Comprehensive Treatment Strategy of Drought in Karst Mountain Areas of Southwest China................................................................. 383 X. Qin, Z. Jiang Study on epikarst water system and water resources in Longhe Region........... 391 W. Lao, F. Lan Hydrogeochemical Characterization of carbonate aquifers of Lepini Mountains .......................................................................................... 399 G.Sappa, L. Tulipano Salt ground waters in the Salento karstic coastal aquifer (Apulia, Southern Italy)..................................................................................... 407 M.D. Fidelibus, G. Cal, R. Tinelli, L. Tulipano An oceanographic survey for the detection of a possible Submarine Groundwater Discharge in the coastal zone of Campo de Dalias, SE Spain..... 417 M.A. Daz-Puga, A. Vallejos, L. Daniele, F. Sola, D. Rodrguez-Delgado, L. Molina, A. Pulido-Bosch Aquifer systems of Epirus, Greece: An overview ............................................. 425 E. Nikolaou, S. Pavlidou, K. Katsanou Application of stochastic models to rational management of water resources at the Damasi Titanos karstic aquifer in Thessaly Greece................. 435 A. Manakos, P. Georgiou, I. Mouratidis
  • xx Contents Solution of operation and exploitation issues of the Almiros (Heraklion Crete) brackish karst spring through its simulation with the MODKARST model............................................................................ 443 A. Maramathas The hydrodynamic behaviour of the coastal karst aquifer system of Zarakas - Parnon (Southeastern Peloponissos) ............................................. 451 I. Lappas, P. Sabatakakis, M. Stefouli Application of tracer method and hydrochemical analyses regarding the investigation of the coastal karstic springs and the submarine spring (Anavalos) in Stoupa Bay (W. Mani Peninsula) ............................................... 459 G. Stamatis, G. Migiros, A. Kontari, E. Dikarou, D. Gamvroula Submarine groundwater discharges in Kalogria Bay, Messinia-Greece: geophysical investigation and one-year high resolution monitoring of hydrological parameters................................................................................ 469 A.P. Karageorgis, V. Papadopoulos, G. Rousakis, Th. Kanellopoulos, D. Georgopoulos Water tracing test of the Ag. Taxiarches spring (South Achaia, Peloponnese, Greece). Infiltration of the Olonos-Pindos geotectonic unit, Upper Cretaceous-Paleocenic carbonate rocks.................................................. 477 N. Tsoukalas, K. Papaspyropoulos, R. Koutsi Effective infiltration assessment in Kourtaliotis karstic basin (S. Crete) .......... 485 E. Steiakakis, D. Monopolis , D. Vavadakis, . Lambrakis The use of hydrographs in the study of the water regime of the Louros watershed karst formations................................................................................ 493 K. Katsanou, A. Maramathas, N. Lambrakis Hydrogeological conditions of the coastal area of the Hydrological basin Almyros, Prefecture Magnesia, Greece............................................................. 503 Ch. Myriounis, G. Dimopoulos, . Manakos Contribution on hydrogeological investigation of karstic systems in eastern Korinthia........................................................................................... 511 K. Markantonis, J. Koumantakis Contribution to the hydrogeological research of Western Crete ....................... 519 E. Manutsoglu, E. Steiakakis
  • Contents xxi Karstic Aquifer Systems and relations of hydraulic communication with the Prespa Lakes in the Tri-national Prespa Basin .................................... 527 . Stamos, . Batsi, . Xanthopoulou Flow geometry over a discharge measuring weir within inclined hydrogeological channels.................................................................................. 535 J. Demetriou, D. Dimitriou, E. Retsinis The contribution of geomorphological mapping in the Ksiromero karstic region: land use and groundwater quality protection......................................... 543 M. Golubovic Deligianni, K. Pavlopoulos, G. Stournaras, K. Vouvalidis, G. Veni The MEDYCYSS observatory, a Multi scalE observatory of flooD dYnamiCs and hYdrodynamicS in karSt (Mediterranean border Southern France) ............................................................................................... 551 H. Jourde, C. Batiot-Guilhe, V. Bailly-Comte, C. Bicalho, M. Blanc, V. Borrell, C. Bouvier, J.F. Boyer, P. Brunet, M. Cousteau, C. Dieulin, E. Gayrard, V. Guinot, F. Hernandez, L. Kong, A. Siou, A. Johannet, V. Leonardi, N. Mazzilli, P. Marchand, N. Patris, S. Pistre, J.L. Seidel, J.D. Taupin, S. Van-Exter Hydrogeological research in Trypali carbonate Unit (NW Crete)..................... 561 E. Steiakakis, D. Monopolis , D. Vavadakis, E. Manutsoglu Volume 2 Fissured rock Hydrogeology Hydrogeological properties of fractured rocks (granites, metasediments and volcanites) under the humid tropical climate of West Africa .............................................. 3 M. Kota, H. Jourde Identification of conductible fractures at the upper- and mid- stream of the Jhuoshuei River Watershed (Taiwan) ..................................................... 11 P.Y. Chou, H.C. Lo, C.T. Wang, C.H. Chao, S.M. Hsu, Y.T. Lin, C.C. Huang Advances in understanding the relation between reservoir properties and facies distribution in the Paleozoic Wajid Sandstone, Saudi Arabia .......... 21 H. Al Ajmi, M. Keller, M. Hinderer, R. Rausch
  • xxii Contents Geoelectrical assessment of groundwater potential in the coastal aquifer of Lagos, Nigeria............................................................................................... 29 K.F. Oyedele, S. Oladele Drainage and lineament analysis towards artificial recharge of groundwater... 37 D. Das Fracture pattern description and analysis of the hard rock hydrogeological environment in Naxos Island, Hellas................................................................. 45 A.S. Partsinevelou, S. Lozios, G. Stournaras Quantitative investigation of water supply conditions in Thassos, N. Greece........................................................................................ 53 Th. Tzevelekis, I. Gkiougkis, Chr. Katimada, I. Diamantis Hydrological properties of Yesilcay (Agva) Stream Basin (NW Turkey) ........ 61 H. Keskin Citiroglu, I.F. Barut, A. Zuran Application of the SWAT model for the investigation of reservoirs creation... 71 K. Kalogeropoulos, C. Chalkias, E. Pissias, S. Karalis Evaluation of geological parameters for describing fissured rocks; a case study of Mantoudi - Central Euboea Island (Hellas) .............................. 81 G. Yoxas, G. Stournaras First outcomes from groundwater recharge estimation in evaporate aquifer in Greece with the use of APLIS method.......................................................... 89 E. Zagana, P. Tserolas, G. Floros, K. Katsanou, B. Andreo Multiple criteria analysis for selecting suitable sites for construction of sanitary landfill based on hydrogeological data; Case study of Kea Island (Aegean Sea, Hellas)......................................................................................... 97 G. Yoxas, T. Samara, L. Sargologou, G. Stournaras Adumbration of Amvrakias spring water pathways, based on detailed geophysical data (Kastraki - Meteora) .............................................................. 105 J.D. Alexopoulos, S. Dilalos, E. Vassilakis Fracture pattern analysis of hardrock hydrogeological environment, Kea Island, Greece ............................................................................................ 113 V. Iliopoulos, S. Lozios, E. Vassilakis, G. Stournaras
  • Contents xxiii Hydrochemistry Geochemical and isotopic controls of carbon and sulphur in calcium- sulphate waters of the western Meso-Cenozoic Portuguese border (natural mineral waters of Curia and Monte Real) ............................................ 125 M. Morais, C. Recio The impact on water quality of the high carbon dioxide contents of the groundwater in the area of Florina (N. Greece)....................................... 135 W. DAlessandro, S. Bellomo, L. Brusca, S. Karakazanis, K. Kyriakopoulos, M. Liotta Pore Water - Indicator of Geological Environment Condition.......................... 145 . bramova, L. bukova, G. Isaeva Nitrogen sources and denitrification potential of Cyprus aquifers, through isotopic investigation on nitrates.......................................................... 151 Ch. Christophi, C.A. Constantinou The behaviour of REE in Agios Nikolaos karstic aquifer, NE Crete, Greece ... 161 E. Pitikakis, K. Katsanou, N. Lambrakis Hydrochemical study of metals in the groundwater of the wider area of Koropi ........................................................................................................... 169 K. Pavlopoulos, I. Chrisanthaki, M. Economou Eliopoulos, S. Lekkas Factors controlling major ion and trace element content in surface water at Asprolakkas hydrological basin, NE Chalkidiki: Implications for elemental transport mechanisms........................................................................................ 177 E. Kelepertzis, A. Argyraki, E. Daftsis Trace and ultra-trace element hydrochemistry of Lesvos thermal springs ........ 185 E. Tziritis, A. Kelepertzis Stable isotope study of a karstic aquifer in Central Greece. Composition, variations and controlling factors ...................................................................... 193 E. Tziritis Evaluation of the geochemical conditions in the deep aquifer system in Vounargo area (SW Greece) based on hydrochemical data .............................. 201 E. Karapanos, K. Katsanou, A. Karli, N. Lambrakis
  • xxiv Contents Phenanthrene Sorption nto Heterogeneous Sediments Containing Carbonaceous Materials in Fresh Water and in Marine Environments: Implications for Organic Pollutant Behavior During Water Mixing................. 211 K. Fotopoulou, G. Siavalas, H.K. Karapanagioti, K. Christanis Hydrochemical investigation of water at Loussi Polje, N Peloponnesus, Hellas ................................................................................................................ 219 R. Koutsi, G. Stournaras Chemistry of Submarine Groundwater Discharge in Kalogria Bay, Messinia-Greece................................................................................................ 229 A. Pavlidou, I. Hatzianestis, Ch. Zeri, E. Rouselaki Chemical characterization of the thermal springs along the South Aegean volcanic arc and Ikaria island............................................................................ 239 S. Karakatsanis, W. DAlessandro, K. Kyriakopoulos, K. Voudouris Application of an in-situ system for continuous monitoring of radionuclides in submarine groundwater sources.................................................................... 249 C. Tsabaris, D.L. Patiris, A. Karageorgis, G. Eleftheriou, D. Georgopoulos, V. Papadopoulos, A. Prospathopoulos, E. Papathanassiou Conceptual Model and Hydrochemical Characteristics of an Intensively Exploited Mediterranean Aquifer...................................................................... 257 V. Pisinaras, C. Petalas, V.A. Tsihrintzis Hydrogeological conditions of the Kotyli springs (N. Greece) based on geological and hydrogeochemical data ............................................................. 265 C. Angelopoulos, E. Moutsiakis Water quality and agriculture Subsurface contamination with petroleum products is a threat to groundwater quality........................................................................................... 275 N. Ognianik, N. Paramonova, O. Shpak Assessment of specific vulnerability to nitrates using LOS indices in the Ferrara Province, Italy....................................................................................... 283 E. Salemi, N. Colombani, V. Aschonitis, M. Mastrocicco Groundwater nitrogen speciation in intensively cultivated lowland areas ........ 291 N. Colombani, E. Salemi, M. Mastrocicco, G. Castaldelli
  • Contents xxv Hydrogeological and hydrochemical characteristics of North Peloponnesus major ground water bodies................................................................................ 299 K. Nikas, A. Antonakos Assessment of natural and human effect in the alluvial deposits aquifer of Sperchios river plain.................................................................................... 307 E. Psomiadis, G. Stamatis, K. Parpodis, A. Kontari Groundwater contamination by nitrates and seawater intrusion in Atalanti basin (Fthiotida, Greece) ................................................................................... 317 V. Tsioumas, V. Zorapas, E. Pavlidou, I. Lappas, K. Voudouris Characterisation of water quality in the island of Zakynthos, Ionian Sea, Western Greece ................................................................................................. 327 G. Zacharioudakis, Ch. Smyrniotis Groundwater vulnerability assessment in the Loussi polje area, N Peloponessus: the PRESK method ................................................................ 335 R. Koutsi, G. Stournaras Intrinsic vulnerability assessment using a modified version of the PI Method: A case study in the Boeotia region, Central Greece............................ 343 E. Tziritis, N. Evelpidou Groundwater vulnerability assessment at SW Rhodope aquifer system in NE Greece ......................................................................................................... 351 A. Kallioras, F. Pliakas, S. Skias, I. Gkiougkis Comparison of three applied methods of groundwater vulnerability mapping: A case study from the Florina basin, Northern Greece...................... 359 N. Kazakis, K. Voudouris Degradation of groundwater quality in Stoupa- Ag.Nikolaos region (W.Mani Peninsula) due to seawater intrusion and anthropogenic effects........ 369 G. Stamatis, D. Gamvroula, . Dikarou, . Kontari Quality Characteristics of groundwater resources in Almyros Basin coastal area, Magnesia Prefecture Greece ..................................................................... 377 Ch. Myriounis, G. Dimopoulos, A. Manakos Quality regime of the water resources of Anthele Sperchios Delta area Fthiotida Prefecture ........................................................................................... 385 N. Stathopoulos, I. Koumantakis, E. Vasileiou, K. Markantonis
  • xxvi Contents Assessment of groundwater quality in the Megara basin, Attica, Greece ......... 393 D. Gamvroula, D. Alexakis, G. Stamatis Environmental associations of heavy and trace elements concentrations in Sarigiol ground water coal basin area ........................................................... 401 K.. Vatalis, K. Modis, F. Pavloudakis, Ch. Sachanidis Marine and human activity effects on the groundwater quality of Thriassio Plain, Attica, Greece...................................................................... 409 V. Iliopoulos, G. Stamatis, G. Stournaras Transport of pathogens in water saturated sand columns.................................. 417 V.I. Syngouna, C.V. Chrysikopoulos A preliminary study for metal determinations in Seawater and Natural Radionuclides in Sediments of Glafkos estuary in Patraikos Gulf (Greece)..... 427 K. Kousi, M. Soupioni, H. Papaeftymiou Purification of wastewater from Sindos industrial area of Thessaloniki (N. Greece) using Hellenic Natural Zeolite....................................................... 435 A. Filippidis, A. Tsirambides, N. Kantiranis, E. Tzamos, D. Vogiatzis, G. Papastergios, A. Papadopoulos, S. Filippidis Geothermics and thermal waters Monitoring heat transfer from a groundwater heat exchanger in a large tank model......................................................................................................... 445 B.M.S. Giambastiani, M. Mastrocicco, N. Colombani Origin of thermal waters of Nisyros volcano: an isotopic and geothermometric survey.................................................................................... 453 D. Zouzias, K.St. Seymour Hydrogeochemical characteristics and the geothermal model of the Altinoluk-Narli area, in the Gulf of Edremit, Aegean Sea ................................ 463 N. Talay, A.M. Gzbol, F.I. Barut Groundwater hydrochemistry of the volcanic aquifers of Limnos Island, Greece ............................................................................................................... 471 G. Panagopoulos, P. Giannoulopoulos, D. Panagiotaras Geothermal exploration in the Antirrio area (Western Greece) ........................ 479 T. Efthimiopoulos, E. Fanara, G. Vrellis, E. Spyridonos, A. Arvanitis
  • Contents xxvii The role of water in constructions projects Sedimentary media analysis platform for groundwater modeling in urban areas..................................................................................................... 489 R. Gogu, V. Velasco, E. Vzquez - Sue, D. Gaitanaru, Z. Chitu, I. Bica Seasonal ground deformation monitoring over Southern Larissa Plain (Central Greece) by SAR interferometry........................................................... 497 I. Parcharidis, M. Foumelis, P. Katsafados Ruptures on surface and buildings due to land subsidence in Anargyri village (Florina Prefecture, Macedonia)............................................................ 505 G. Soulios, Th. Tsapanos, K. Voudouris, T. Kaklis, Ch. Mattas, M. Sotiriadis
  • Fissured rock Hydrogeology
  • 3 Hydrogeological properties of fractured rocks (granites, metasediments and volcanites) under the humid tropical climate of West Africa M. Kota1 , H. Jourde Laboratoire HydroSciences Montpellier UMR 5569 Universit Montpellier 2 Place E. Bataillon, 34095 Montpellier Cedex 5, France 1 Now at International Institute for Water and Environmental Engineering (2iE), 1 rue de la Science, 01 BP 594 Ouagadougou 01 Burkina Faso [email protected] Abstract This study aims to propose a vertical structuring of water production zones for three types of fractured rocks encountered in Ivory Coast, West Africa. In a first step, the methodology consists of the characterization of the weathering profiles based on: i) bedrocks and weathering layers observations at outcrop; ii) interpretation and synthesis of geophysical data and lithologs from different bore- holes. In a second step, the evolution with depth of flow rate (air-lift discharge rates) as well as the frequency and the density of water production zones during drilling are statistically analyzed. Then, the distributions of these various proper- ties versus the depth are fitted to probability laws. For each of the geological for- mations (granites, metasediments and volcanites) the related weathering profile comprises, from top to bottom, four separate layers: alloterite, isalterite, fissured layer and fractured fresh basement; these weathering profiles are systematically covered by a soil layer. In granites, the maximal values of flow, frequency and density of the water production zones (WPZ) are situated around 40 m depth sys- tematically within the fractured fresh granite layer. In metasediments and volcan- ites, the maximal values of flow, as well as the maximal frequency and density of WPZ are identified at two distinct depths. The first WPZ, around 40 m depth, is associated to the fissured layer for both profiles; the second WPZ, around 80 m depth is associated to the fractured fresh sandstone layer for the weathering pro- file in metasediments and to the fractured fresh metabasalt layer, for the weather- ing profile in volcanites. 1 Introduction Hard rocks show vertical and horizontal heterogeneities as a result of both the spa- tial variation of the lithology, as well as the geometric and hydraulic properties of their distinct composite parts. This complexity of the aquifer limits the ability of N. Lambrakis et al. (Eds.), Advances in the Research of Aquatic Environment, Vol. 2 DOI 10.1007/978-3-642-24076-8, Springer-Verlag Berlin Heidelberg 2011
  • 4 M. Kota, H. Jourde hydrogeologists to fully understand, describe and predict the hydrodynamic be- havior of this type of hydrosystem. The scarcity of available data, their inconsis- tencies with the potential conceptual processes and mechanisms to be predicted, and their inherent ambiguity do not justify the promotion of models that include all mechanisms in a deterministic manner (Finsterle et al. 2002). Recognizing this limitation, several authors (Geirnaert et al. 1984; Wright 1992; Taylor and How- ard 2000; Freyssinet and Farah 2000; Dewandel et al. 2006) developed conceptual models describing simplified lithological sequences above the crystalline base- ment. Most of these studies concerned granite formation, and few investigations addressed volcanosedimentary formations. Their heterogeneity may be the reason why no conceptual model is proposed for these formations. This study aims to propose a standard hydrogeological conceptual model for granite and volcanosedimentary rocks describing water production zones as a function of the vertical layering of each geological formation weathering profile under humid tropical climate condition. 2 Geological context of the Dimbokro catchment Dimbokro catchment (6300 km2 ) in which many hydrogeological data are avail- able is chosen as a study case to characterize granites, metasediments and volcan- ites. This catchment is part of the Nzi River catchment located in the central east of Ivory Coast, West Africa (Fig. 1). The rocks set up is attributed to the Birimian tectono-volcanism phase (2000-1880 million years ago (my)) that af- fect lower proterozoic formations in many part of west Africa (Ivory Coast, Burk- ina Faso, Ghana, Niger etc.). Birimian derives from Birim the name of a river in Ghana and refers to volcanites as well as to volcanosedimentary and detritical sediment deposits, set up within numerous furrows or intercratonic basins The geological formations of Dimbokro catchment are roughly divided into two major groups which experienced different tectono-metamorphic changes (Yao et al. 1990, 1995): i) the volcanosedimentary complex and ii) the biotite granites. Synthesis of the geological history is made by Peltre (1977) and Yao et al. (1995). Set up of the granites domain began at Liberian tectono-volcanism (2900 to 2400 my) and precedes the volcanosedimentary domain. In Lower Proterozoic, the reactivation of deep faults by Eburnean tectono-volcanism phase (about 2200 my) remobilizes Liberian granites and opened in the Liberian platform long and narrow subsidence. At this period, interstratifications of lava and associated sediments flowed out through marginal faults towards an open sea, and formed the volcanosedimentary complex. The Birimian tectono-volcanism phase (2000 to 1880 my) also called main deposit phase rejuvenated granites rocks and generated thick detrital accumula- tions made of conglomerates and sandstones, overlaying volcanosedimentary rocks. This accumulation phase supposes the existence of a high relief and strong erosion due to intense tectonic movements. Then the detrital accumulation coming
  • Hydrogeological properties of fractured rocks under the climate of West Africa 5 from erosion processes is folded during this tectonic paroxysm, which transformed this volcanosedimentary complex formation into schists. The metamorphism poorly affected the volcanosedimentary complex formations. These formations show a clayey tendency with grey or green colour passing in yellow green depend- ing on rock weathering degree. The study site is under the influence of the intertropical convergence with a pluviometric regime characterized by two rainy seasons. The first one is situated between April and June. The second extends between September and November. The average rainfall of the study site is 1200 millimeters. Fig. 1. Geology of the Dimbokro catchment. 3 Vertical structuring of the weathering profiles as a function of the geological units The interpretation of lithologs (obtained from the cuttings collected each meter, during the drilling phase) and geophysical data (vertical electrical sounding) on the one hand, and the field observation (weathering profiles, as well as granites and volcanosedimentary bedrocks on outcrops) during the field campaign of 2008 and 2009 on the other hand are considered for characterizing the vertical structur- ing of granites and volcanosedimentary formations. Observation at outcrop and the analysis of 32 lithologs for granites, 33 lithologs for metasediments and 37 lithologs for volcanites reveal that vertical layering of the weathering profile in each rock type comprises from the top to the bottom the following separated layers (Fig. 2): alloterite, isalterite, fissured layer and frac- tured fresh basement. Each profile is covered by a soil layer. Though granites, metasediments and volcanites of the Dimbokro catchment ex- perience the same weathering and erosion cycles during the paleoclimatic fluctua- tions from Eocene to recent quaternary period, they exhibit many differences and
  • 6 M. Kota, H. Jourde similarities. In granites, the weathering profile is relatively thin due to the absence of iron crust which protects weathering products against dismantling. In metasediments iron crusts develop better than in granites; in these rocks the alterite (alloterite and isalterite) is of kaolinitic type and thus more resistant to dismantling. Consequently, metasediments exhibit thicker profiles than granites. Fig. 2. Vertical layering of the weathering in granite, metasediment and volcanites. In volcanites, the weathering profiles are generally complete and have the larg- est thickness, which again is related to a well developed iron crust that protect the rocks from dismantling. The high reliefs associated with the rocks show that they have been subjected to less dismantling than metasediments and granites. In each profile, the fissured layer is dominated by horizontal fissures (discontinuities in the alteration zone). But the structures of the fresh basement are different: In granites, the fractured fresh basement comprises a predominance of horizon- tal fractures (discontinuities in the fresh basement) In metasediments and volcanites the fractured fresh basement is characterized by vertical fractures intersected by horizontal discontinuity due to quartz veins intrusions. Regarding the thicknesses it is noted that: In granites, alloterite, isalterite and fissured layers have similar thicknesses.
  • Hydrogeological properties of fractured rocks under the climate of West Africa 7 In metasediments, the thickness of the fissured layer is lower than the ones of the alloterite and isalterite layers that both have similar thicknesses. In volcanites, the thickness of the fissured layer is also lower than the one of the alloterite and isalterite layers. 4 Vertical structuring of water production zones (WPZ) in the different geological units In order to better understand the hydrodynamic behavior of the weathered mantle and the fractured basement, the WPZ associated with conductive fracture zones are characterized according to the depth from the top of the weathering profile (in- terface soil/ alloterite). The evolution of flows (air-lift discharge rates) and both the frequency and the density of water production zones during drilling is studied statistically. Then, the distributions of these various parameters versus depth are fitted to probability laws (Fig. 3). The flow rates of each class of depth in granites, metasediments and volcanites are obtained by using the geometric means of air lift flow rates recording in each class of depth. The choice of geometric means is linked to the fact that it takes into account the disparities (standard deviation) in flow rates between the classes of depth in the same rock on one hand and between in the classes of depth in the three types of rocks on the other hand. Evolution of flow rates (air lift discharge rates) according to depth shows that the most important flows are recorded in volcanites. Indeed, in volcanites, flow rates grow with depth and reach a maximum of 5 m3 /h between 80 and 100 m (in the fractured fresh metabasalt layer) before a drastic decrease. In metasediments, the maximums of flows are observed between 40 and 60 (in fissured layer) and between 80 and 100 m (in fractured fresh sandstone) with almost identical air lift discharge rates of 2.75 m3 /h. Beyond 100 m this discharge decreases with the depth. Compared to metasediments, granites show lower flows. In granites, flow increases until a maximum of 1.8 m3 /h between 40 and 60 m (in fractured fresh granites layer). In metasediments and volcanites, WPZ are undifferentially localized in isalter- ite layer, fissured layer and fractured fresh basement layer while in granites, they are only localized in fissured layer and fractured fresh basement. In each of the profiles, the frequency of WPZ (all layers of the profile having been taken into ac- count) is distributed in a log-normal way. In granites and metasediments, WPZ are observed from 10 m and up to 80 and 100 m below the top of the weathering pro- file. The maximum of WPZ is observed at about 45 m depth for both the weather- ing profile in granite (in the fractured fresh granites layer) and in metasediments (in the fissured layer). In volcanites, the occurrence of WPZ is deeper; it extends between 30 m and 110 m below the top of the weathering profile.
  • 8 M. Kota, H. Jourde In granites, evolution of density (number of WPZ per unit length of WPZ) re- veals that the highest density of WPZ is localized between 40 m and 60 m depth (in the fractured fresh granites layer), around 40 m depth in metasediments (in the fissured layer) and around 60 m depth in volcanites (in the fissured layer). Even if the densities are in the same order of magnitude, the highest densities (29 x 10-2 ) of WPZ are recorded in volcanites and in granites and the lowest (24 x 10-2 ) in metasediments. Fig. 3. Evolution of frequency, density and rates of WPZ according to depth. a. in granites. b. in metasediments. c. in volcanites.
  • Hydrogeological properties of fractured rocks under the climate of West Africa 9 Below this highest density level, the density of WPZ decreases with depth for each of the profiles. However, a significant increase of the density of WPZ occurs around 80 m depth in metasediments; this level is associated to fractured fresh sandstone layer. The same phenomenon is also observed in granites and volcanites around 75 and 100 m respectively, but in a slightly less significant manner. In hard rocks, this decrease of fracturing density with depth was described by the works of Wyns et al. (1999 and 2002), and Dewandel et al. (2006). The simultaneous analysis of the evolution of the frequencies, the densities and the flows of WPZ shows that in granites and metasediments, the evolution of the flows of WPZ is coherent with those of the frequencies and densities; while in volcanites, the evolution of flows of WPZ is coherent with those of frequency and densities in the first 60 m depth. Beyond 60 m depth, it is not the case anymore: the class of depth associated with the maximal flows corresponds to the class of depth for which the frequency and the density of WPZ are not high. In volcanites, deepest wells are the most productive. For these wells, the deep fractures are localized in fractured fresh mtabasalte layer characterized by low frequency and density of WPZ. High flows supplied by these fractures are proba- bly related to their size (regional fault) or to their interconnection with other sys- tems of fractures. Many studies defined the optimal depth that a drilling has to achieve to obtain a satisfactory productivity in hard rocks (Taylor and Howard 2000). Most of these studies showed that the productivity decreases with depth, what was interpreted for a long time as being associated with closure of fractures because of the lithostatique pressure (Berger et al. 1980) in depth; the present study and the other works (Wyns et al. 1999; Dewandel et al. 2006; Neves and Morales 2007) show that the decrease of the productivity with the depth would also be related to the decrease of the density of fractures in-depth. 5 Conclusions Weathering profile characterization in granites, metasediments and volcanites in Dimbokro catchment reveals that each of the three profiles comprises four sepa- rate layers overlaid by a soil layer (alloterite, isalterite, fissured layer and frac- tured fresh basement). In granites, the weathering profile is relatively thin. Meta- sediments exhibit thicker profiles than granites. In volcanites, the weathering profiles are generally complete and have the largest thickness. As hydrogeological impacts of this geological structuring, occurrence of WPZ is less deep in granites and metasediments than in volcanites. WPZ are localized undifferentially in isaltrite layer, fissured layer and fractured fresh basement in metasediments and volcanites while in granites, they are only localized in fissured layer and fractured fresh basement.
  • 10 M. Kota, H. Jourde In the framework of water resource exploitation in granites, metasediments and volcanites localized in West Africa under humid tropical climate, future hydraulic campaigns should constrain the drilling depth limit according to the geological domains and taking into account the classes of depth associated to the highest fre- quency, density and flow rates of WPZ. This will allow obtaining a good yield in terms of well productivity and hydraulic campaign cost. References Berger J, Camerlo J, Fahy J.C, Haubert M (1980) Etude des ressources en eaux souterraines dans une rgion de socle cristallin: la Boucle de cacao en Cte dIvoire. Bull. BRGM. Sr. II. Sect. III. 4, 3350-338 Dewandel B., Lachassagne, P., Wyns R., Marchal J C., Krishnamurthy NS (2006) A general- ized 3-D geological and hydrogeological conceptual model of granites aquifers conrolled by single or multiphase weathering, Journal of Hydrology 330, 260-284 Finsterle, S., Fabryka-Martin JT., Wang JSY (2002) Migration of a water pulse through fractured porous media. Journal of contaminant Hydrology 54 (2002) 37-57 Freyssinet P., Farah A S (2000) Geochemical mass balance and weathering rates of ultramafic schists in Amazonia, Chemical Geology 170 (2000), 133-151 Geirnaert W, Groen M, Van Der Sommen J, Leusink A (1984) Isotope studies as a final stage in groundwater investigations on the African shield, challenges in African Hydrology and water resources (Proceeding of the Harare Symposium, July 1984). IAHS publ. 144, 141-153 Neves M A, Morales N (2007) Well productivity controlling factors in crystalline terrains of southeastern Brazil, Hydrogeology Journal 15, 471-482 Peltre P (1977) Le V baoul: Hritage gomorphologique et paloclimatique dans le trac du contact fort-savane, Cahier ORSTOM, 190 Taylor R., Howard K (2000) A tectono-geomorphic model of the hydrogeology of deeply weath- ered crystalline rock: Evidence from Uganda, Hydrogeology Journal, 8:279-294 Wright E P (1992) The hydrogeology of crystalline basement aquifers in Africa, Geological So- ciety, London, Special Publications, Vol. 66, doi: 10. 1144/GSL.SP.1992.066.01.01, 1-27 Wyns R., Gourry JC., Baltassat JM., Lebert F (1999) Caracterisation multiparametres des hori- zons de subsurface (0-100 m) en contexte de socle altr. In: I. BRGM, IRD, UPMC (Eds), 2me Colloque GEOFCAN, Orlans, France, 105-110 Yao D, Delor C, Gadou G, Kohou P, Okou A, Konat S, Diaby I (1995) Notice explicative de la carte gologique feuille de Dimbokro, Mmoire SODEMI, Abidjan (Cte dIvoire)
  • 11 Identification of conductible fractures at the upper- and mid- stream of the Jhuoshuei River Watershed (Taiwan) P.Y. Chou, H.C. Lo, C.T. Wang, C.H. Chao, S.M. Hsu, Y.T. Lin, C.C. Huang Geotechnical Engineering Research Center, Sinotech Engineering Consultants, Inc., No. 7, Lane 26, Yat-Sen Road, Taipei 110, Taiwan [email protected] Abstract The movement and storage of ground water in the mountainous re- gion has a significant impact on the dynamics of surface water flow. An adequate identification of the conductible fracture in the aquifer has thus received growing interest over the past decades. This paper summarizes the major findings from the first year of a hydrogeological investigation program initiated by the Central Geo- logical Survey, Ministry of Economic Affairs (MOEA) of Taiwan since 2010, with a special focus on exploring in detail the fracture permeability. During the on-site investigation, geophysical logging was applied to delineate the lithostrati- graphic characteristics of bedrock aquifers. The hydraulic conductivity of 67 ob- servation segments was estimated by the constant head injection method. From the information gathered in this study, the hydraulic conductivities of the identified fractured medium above a depth of 40m are more than one order higher than that of the matrix. The occurrence of ground water in a fracture network, however, is found to be not solely governed by lithological composition, but more possibly by fracture porosity and spacing. A simple linear relationship was found by plotting the hydraulic conductivity against the product of total porosity and cubic aperture ratio (fracture spacing/sealed-off interval between the packers). 1 Introduction Accompanying with the growing concern on the sustainability of available water resource, to gain more in-depth knowledge on the potential yield of aquifers is a crucial task. The movement of ground water within the mountainous region is ei- ther dominated by fracture continua, the porous medium, or even by both. The connectivity of discontinuities and the vector gradient of hydraulic heads are likely the most important factors determining the fracture/matrix permeability. Prior to evaluating whether a specific stratum of geometry is capable of yielding and storing a sufficient amount of ground water by means of any sophisticated numerical models, it is necessary to perform the downhole geophysical investiga- tion to gain more insights into the lithologic composition of stratum unit. N. Lambrakis et al. (Eds.), Advances in the Research of Aquatic Environment, Vol. 2 DOI 10.1007/978-3-642-24076-8, Springer-Verlag Berlin Heidelberg 2011
  • 12 P.Y. Chou et al. The identification of conductible fracture in the mountainous-foothill region is often difficult. Within a fractured aquifer network, usually, not all the perceptible fractures will be hydrologically connected. The use of a combination of composite well logs and in-hole tracer tests could provide more than sufficient information regarding to the complex geometries and layering, however, especially when working with limited budget and time, a set of systematic and concise criteria for the quick in-situ identification of conductible fractures is indeed required. The Central Geological Survey, Ministry of Economic Affairs (MOEA) of Taiwan has initiated a large-scale hydrogeological investigation program since 2010 that aimed at exploring in detail the hydraulic properties of bedrock aquifers in Taiwan mountainous-foothill region. This study presents estimates of hydraulic conductivity obtained by the constant head injection test and, further, to assess the relationship among hydraulic conductivity, fracture porosity and spacing. 2 Geological setting The study area is located in the Western Foothills of Taiwan within the latitude and longitude of 23 52' N and 120 25' E, respectively. It covers the up- and mid- dle-stream basin of the Jhuoshuei River with an area of 1,577 square kilometer. As shown in Fig. 1, the elevation lies between 142 and 1658 meters above sea level (m.a.s.l.). Owing to the collision of tectonic plates (Mouthereau and Lacombe 2006) a series of westward fold-and-thrust belts can be observed. The geological formation in this study area can be roughly separated from East to West into four regions by the orientation of faults. Region I at the most eastern side ranges in age from Eocene to Miocene, where the predominant lithology is massive slate rock accompanied with metasandstones and metasiltstones. Region II extends from Eo- cene to early Oligocene, the upper part is dominated by hard shale stone and the lower part is coarse quartz sandstone hosted. Region III, bounded by the Shuilikeng, Chelungpu and Tachienshan faults, is underlain by Miocene to Pleis- tocene sedimentary rocks. A distinct pattern of lithological distribution can be found in this region that closely related to the influence of folding, faulting and metamorphism. Region IV at the most western side is mainly consisted of uncon- solidated alluvium and relatively young deposits from late Pliocene to Pleistocene. Topographic slopes in region I, II and III are from 30-60, relatively, more gentle topographic slopes (0-30) are found in the region IV. A total of 29 vertical fully penetrating boreholes (see Table 1) were drilled to a depth of 100 meters (328ft.) below the land surface. The ground water level (m) from the earth surface was measured on-site during the test in the wet season.
  • Identification of conductible fractures of the Jhuoshuei River Watershed (Taiwan) 13 Table1.Boreholesdescription. TopographicregionIIIIII BoreholeB11B12B13B02B10B21B04B05B06B08B09B16B17B18 Geometricheight (m.a.s.l.) 391472468431357638409295764633403280227631 Groundwaterlevelbe- neaththesurface(m) 14.077.086.14.59.036.54.511.010.04.016.514.34.023.0 TopographicregionIIIIV BoreholeB19B20B22B24B25B26B27B29B01B03B07B14B15B23B28 Geometricheight (m.a.s.l.) 476165894375671211721911201316142345341312749188 Groundwaterlevelbe- neaththesurface(m) 20.053.013.013.315.47.06.018.52.04.04.780.028.59.08.8
  • 14 P.Y. Chou et al. Rock samples were recovered and allowed for an initial on-site lithostratigraphic identification, as well as various laboratory analyses afterward. Fig. 1. Geological map of the study area. 3 Methodology In each borehole a series of borehole loggings were conducted in situ to identify the probable pathways of ground water. The electric log and the full waveform sonic log (from Robertson Geologging Ltd. UK) were adopted. These two sondes have long been used in the field of geosciences, a comprehensive overview has been provided in the study of Timur and Toksoz (1985), and Lau (1998). In this present research, the electric log was used to measure the spontaneous potential, electrical resistivity and natural gamma radiation, while the full waveform sonic log was applied to detect the sonic travel-time at a specific depth within the bore- hole. By using the acoustic-velocity logging, aquifer porosity can also be deter- mined based on a time-average equation. Borehole televiewer was performed to un-wrap the oriented circular borehole- wall images, which facilitated the interval of interest can be precisely straddled when performing packer tests. In addition, the fracture related characteristics such as the dip-azimuth, aperture width, and infilling material of fractures can also be quantified by further mapping efforts. The application of borehole televiewer on
  • Identification of conductible fractures of the Jhuoshuei River Watershed (Taiwan) 15 fracture identification has been adopted in earlier studies (Hartenbaum and Raw- son 1980; Williams and Johnson 2004; Morin 2005; Hubbard et al. 2008). Two types of televiewer were adopted in this project to identify the appearance of frac- ture zones: the high resolution acoustic televiewer (HiRAT) and the optical televiewer (OPTV) (from Robertson Geologging Ltd. UK). The maximum pres- sure allowance of both types of televiewer is 20MPa. Based on the geophysical log and televiewer profiles, four criteria were taken into consideration to identify the conductible fractures: (1) Reduced gamma-ray response; (2) Divergence of the short normal-resistivity log relatively to the long one; (3) Larger acoustic-velocity derived porosity; (4) Appearance of discernible spacing (>0.01m). Since after the conductible fractures in each borehole were identified, the hydraulic conductivity of the selected observation segments was de- termined by the constant head injection test (CHIT) with double packers system. This technique has been widely employed elsewhere to determine the hydraulic properties of a fractured stratum (e.g. Morin et al. 1988; Howard et al. 1992; Brown and Slater 1999; Niemi et al. 2000; Mejas et al. 2009). The detailed appa- ratus of the double packer assemblies employed in this study were described by Ku et al. (2009), and the procedures of testing were following the designation of American Society for Testing and Materials method (ASTM D4630-96 2002). The sealed-off interval was fixed at 1.5m. Water was injected with a constant pressure of 0.2Mpa or at least in excess of the ambient hydrostatic heads. At least two observation segments were specified in each borehole. To diminish the risk of failure due to borehole spalling, the packer testing was carried out from the obser- vation segment located at the lowest position in the borehole and then moving upward to the next. Each test took at least three hours including rig transfer, quick calibration, packer inflation, data recording and pressure recovery. The variation of hydraulic head and injected flow rate within the testing section were recorded per second and stored in a data-logger developed by the Sinotech Inc. 4 Data analysis and interpretation Sixty seven observation segments, including both fractured and non-fractured me- dia (matrix) in consolidated bedrock, were tested by CHIT. Hydraulic conductivity was derived by the interpretation of injected flow rate with the software AQTESOLV, version 4.5 (HydroSOLVE Inc. Reston, VA). In this study, the gen- eralized radial flow model proposed by Barker (1988) was adopted and written as: r h r rr K t h S n ns 1 1
  • 16 P.Y. Chou et al. where Ss represents the specific storage of aquifer [L-1 ]; h(r, t) denotes the change in hydraulic head [L] with time, r represents the radial distance from the borehole [L]; K represents the hydraulic conductivity [LT-1 ]; n denotes the flow dimension according to the distance from the borehole (1 for linear flow, 2 for cylindrical flow, 3 for spherical flow). The magnitudes of hydraulic conductivity are plotted on a logarithmic scale against the depth in borehole as shown in Fig. 2. The corre- sponding distribution of the magnitudes with respect to the occurrence of fractures as well as the type of rock is also presented. -120 -80 -40 0 1.E-09 1.E-07 1.E-05 1.E-03 Hydraulic conductivity (m/sec) Depthofobservationsegment(m) Fractures of metamorphic rock Matrix of metamorphic rock Fractures of sedimentary rock Matrix of sedimentary rock Fig. 2. Plot of the estimated hydraulic conductivity on a logarithmic scale with respect to different types of rock against depth in borehole. The estimated hydraulic conductivity above a depth of 40m (i.e. the upper part of bedrock lying beneath the regolith layer) seems to show a slightly higher mag- nitude than at the greater depth, however, the overall hydraulic conductivities ap- pear to be no significant depth correlation. With a view to evaluate the water- bearing capacity of fracture and matrix, a further subdivision can be made in terms of the magnitude of hydraulic conductivities as follows: (1) semi conductible me- dium: 10-5 < K < 10-3 m/s; (2) partial conductible medium: 10-7 < K < 10-5 m/s; (3) non-conductible medium: K < 10-7 m/s. It is found that the identified fractures at the upper part of the bedrock possess semi-to-partial conductive capacity, while the fractures at the lower part of the bedrock exhibit a wider range of distribution pattern. Additionally, the occurrence of fractures in this study area shows ap- proximately one order of higher hydraulic conductivity than of the matrix. Fig. 3 attempts to further reveal the correlation of hydraulic conductivity (K) between total porosity (derived from acoustic velocity), and aperture ratio (frac- ture spacing/sealed-off interval between the packers, 1.5m). The open fractures with spacing less than 0.01m are not taken into account.
  • Identification of conductible fractures of the Jhuoshuei River Watershed (Taiwan) 17 Y = 2254 X, R2 = 0.14 Pearson correlation coefficient, r = 0.16 (n = 45) 0.0 0.2 0.4 0.6 0.8 1.0 1.E-09 1.E-08 1.E-07 1.E-06 1.E-05 1.E-04 1.E-03 Hydraulic conductivity (m/sec) Porosity(%) Y = 4626 X, R2 = 0.29 Pearson correlation coefficient, r = 0.30 (all identified fractures, n = 45) Pearson correlation coefficient, r = 0.54 (data without outliers, n = 40) 0.0 0.2 0.4 0.6 0.8 1.0 1.E-09 1.E-08 1.E-07 1.E-06 1.E-05 1.E-04 1.E-03 Hydraulic conductivity (m/sec) Apertureratio(%)Y = 2532 X, R2 = 0.58 Pearson correlation coefficient, r = 0.41 (all identified fractures, n = 45) Pearson correlation coefficient, r = 0.76 (data without outliers, n = 40) 0.0 0.2 0.4 0.6 0.8 1.0 1.E-09 1.E-08 1.E-07 1.E-06 1.E-05 1.E-04 1.E-03 Hydraulic conductivity (m/sec) PorosityApertureratio Y = 2269 X, R2 = 0.69 Pearson correlation coefficient, r = 0.44 (all identified fractures, n = 45) Pearson correlation coefficient, r = 0.84 (data without outliers, n = 40) 0.0 0.2 0.4 0.6 0.8 1.0 1.E-09 1.E-08 1.E-07 1.E-06 1.E-05 1.E-04 1.E-03 Hydraulic conductivity (m/sec) Porosity(Apertureratio)3 Fig. 3: Hydraulic conductivity in the logarithm scale versus total porosity (up-left), aperture ratio (up-right), product of total porosity and aperture ratio (down-left), and product of total porosity and cubic aperture ratio (down-right). As shown in Figure 3, when considered individually, there is only a weak posi- tive correlation found between hydraulic conductivity and the total porosity (Pear- son's r = 0.16), while a moderate correlation is found with respect to the aperture ratio (Pearson's r = 0.30, all data included; Pearson's r = 0.54, excluding outliers). Interestingly, a slightly stronger correlation (Pearson's r = 0.41, all data included; Pearson's r = 0.76, excluding outliers) is shown when plotting the product of total porosity and aperture ratio versus the hydraulic conductivities. It indicates that the transport of ground water does not controlled by either the intra-aggregate pores, or the inter-aggregate spacing alone, but regulated by both proportionally. After exploring various possible relations, a simple linear relationship (Hydraulic con- ductivity K = 0.00044[Porosity (Aperture ratio) 3 ], coefficient of determination R2 = 0.69) was identified by plotting the hydraulic conductivity against the prod- uct of total porosity and cubic aperture ratio. Note that this relationship has not taken the fracture orientation into account. A further testing of this relation with respect to three-dimensional fracture orientation is recommended.
  • 18 P.Y. Chou et al. 5 Discussions and recommendations This paper reports the summary of a just-completed project aiming toward under- standing the fracture permeability in mid-Taiwan mountainous-foothill region. It is also the purpose of this study to provide a theoretical and empirical based guide- line for quick identification of conductible fractures. On the basis of 29 vertical boreholes at the upper- and mid-stream site of Jhuoshuei River basin, the conjunc- tive use of geophysical logging and televiewer imaging was carried out and used for determining the lithologic characteristics. Four hypothesized criteria were pro- posed which are applicable to identify the presence of permeable zone. The hy- draulic conductivity at the predetermined depths was estimated by the constant head injection method. According to the data collected during the first year, it is found that the major- ity of the identified fractured medium, especially above a depth of 40m, shows more than one order of higher hydraulic conductivity than of the non-fractured medium. However, the transport of ground water in the mountainous region does not independently controlled by either the inter-aggregate spacing, or the intra- aggregate pores alone, but, possibly, regulated by both proportionally. A simple linear relationship was identified by plotting the hydraulic conductivity against the product of total porosity and cubic aperture ratio. This relation could provide as an initial guide in assessing the potential yield of aquifer with the help from a drilling borehole. More systematic research is needed to formulate this relation with re- spect to fracture orientation. References Barker JA (1988) A generalized radial flow model for hydraulic tests in fractured rock. Water Resour Res 24, 1796-1804 Brown D., Slater LD (1999) Focused packer testing using geophysical tomography and CCTV in a fissured aquifer. Q. J. Eng. Geol. Hydrogeol. 32, 173-183 Hartenbaum BA, Rawson G (1980) Subsurface Fracture Mapping from Geothermal Wellbores, U. S. Department of Energy Report DOE/ET/27013-T1 Howard KWF, Hughes M, Charlesworth DL, Ngobi G (1992) Hydrogeologic Evaluation of Fracture Permeability in Crystalline Basement Aquifers of Uganda. Hydrogeol. J. 1, 55-65 Hubbard B, Roberson S, Samyn D, Merton-Lyn D (2008) Instruments and Methods - Digital op- tical televiewing of ice boreholes. J. Glaciol. 54, 823-830 Ku CY, Hsu SM, Chiou LB. Lin GF (2009) An empirical model for estimating hydraulic con- ductivity of highly disturbed clastic sedimentary rocks in Taiwan. Eng. Geol. 109, 213-223 Lau KC (1998) A review of downhole geophysical methods for ground investigation. Technical Note No. TN 4/98, Geotechnical Engineering Office, Hong Kong Mejas M, Renard P, Glenz D (2009) Hydraulic testing of low-permeability formations: A case study in the granite of Cadalso de los Vidrios, Spain. Eng. Geol. 107, 88-97 Morin RH (2005) Hydrologic properties of coal beds in the Powder River Basin, Montana I. Geophysical log analysis. J. Hydrol. 308, 1-4
  • Identification of conductible fractures of the Jhuoshuei River Watershed (Taiwan) 19 Morin RH, Hess AE, Paillet FL (1988) Determining the Distribution of Hydraulic Conductivity in a Fractured Limestone Aquifer by Simultaneous Injection and Geophysical Logging. Ground Water. 26, 587-595 Mouthereau F., Lacombe O (2006) Inversion of the Paleogene Chinese continental margin and thick-skinned deformation in the Western Foreland of Taiwan. J. Struct. Geol. 28, 1977-1993 Niemi A, Kontio K, Kuusela-Lahtinen A, Poteri A (2000) Hydraulic characterization and upscal- ing of fracture networks based on multiple-scale well test data. ater Resour. Res. 36, 3481- 3497 Timur A., Toksoz MN (1985) Downhole geophysical logging. Annu. Rev. Earth Planet. Sci. 13, 315-344 Williams JH, Johnson CD (2004) Acoustic and optical borehole-wall imaging for fractured-rock aquifer studies. J. Appl. Geophys. 55, 151-159
  • 21 Advances in understanding the relation between reservoir properties and facies distribution in the Paleozoic Wajid Sandstone, Saudi Arabia H. Al Ajmi1 , M. Keller2,4 , M. Hinderer3 , R. Rausch4 1 Ministry of Water and Electricity, Water Resources Development Department, Riyadh, Saudi Arabia, email: [email protected] 2 Geozentrum Nordbayern, Abteilung Krustendynamik, Schlossgarten 5, 91054 Erlangen, Germany 3 Institut fr Angewandte Geowissenschaften, TU Darmstadt, Schnittspahnstrasse 9, 64287 Darmstadt, Germany 4 Gesellschaft fr Technische Zusammenarbeit International Services (GTZ-IS), Riyadh, Saudi Arabia Abstract The Wajid Sandstone is one of the most important groundwater reser- voirs in the Kingdom of Saudi Arabia. The knowledge of the dimensions and the distribution of its sedimentary facies are essential for high quality reservoir inter- pretation. Hitherto, the facies and their dimensions are only roughly known from extrapolation of subcrop data and geophysical surveys. Sedimentological logging and correlation of the sections led to an interpretation of the depositional processes and a more detailed facies model. Based on system- atic lithofacies and architectural element analysis, the so far established and pub- lished facies characteristics derived from subcrop information of the depocenter in the West of the Kingdom and also from the outcrop area have to be modified. These data have important implications on reservoir properties of the Wajid sandstone. The sandy deposits guarantee a high primary porosity and permeability up to 1 D. Bioturbation leads to pronounced anisotropy in some horizons. Of ma- jor importance, however, are late diagenetic cementation effects which focus on faults, fractures and horizontal to subhorizontal discontinuities. Most widespread is iron cementation which makes up almost impermeable seals and separates res- ervoirs horizontally and vertically. The primary control on reservoir quality is due to a gradual facies change from W to E. Fine-grained silty layers are increasingly intercalated towards the E but are almost completely absent in the W. Conse- quently, in the western area, the Wajid Group forms a combined reservoir but in the subsurface is separated into two layers. N. Lambrakis et al. (Eds.), Advances in the Research of Aquatic Environment, Vol. 2 DOI 10.1007/978-3-642-24076-8, Springer-Verlag Berlin Heidelberg 2011
  • 22 H. Al Ajmi et al. Introduction In Saudi Arabia, the Paleozoic Wajid Sandstone is an important groundwater res- ervoir and in the subsurface, several individual aquifers have been distinguished (GTZ-DCo 2007). The properties of the individual aquifers and their correlation to facies and depositional environment, however, are only poorly known. We present preliminary results of a detailed investigation on facies, lithology, and depositional environment in the Wajid Sandstone (Fig.1). It is subdivided into five formations, the Dibsiyah, Sanamah, Qalibah, Khusayyayn, and Juwayl formations (Kellogg et al. 1986). Fig. 1. Outcrops of the Wajid Sandstone and its members (modified from Al Husseini, 2004) in SW Saudi Arabia.
  • Advances in understanding the relation between reservoir properties and facies distribution 23 In general, biostratigraphic control on the deposits of the Wajid Sandstone is very poor. It has been dated mainly indirectly through correlation of geophysical data to the subsurface (Evans et al. 1991). Following this correlation, the Dibsiyah is of Cambrian or Ordovician age; the Sanamah corresponds to the latest Ordovi- cian. The Qalibah is interpreted to correspond to the Early Silurian, while the Khusayyayn was deposited during Devonian and Early Carboniferous time. The Juwayl comprises glacigenic deposits and their formation is attributed to the Up- per Carboniferous and Lower Permian glaciation. Dibsiyah Formation The Dibsiyah is a succession of medium-grained to conglomeratic sandstones with few intercalations of finer siliciclastic horizons. The Dibsiyah is subdivided into a lower and an upper part. The lower unit has a minimum thickness of about 60 m at Jabal Dibsiyah, the upper part a minimum thickness of 130 m. The lower Dibsiyah consists of a succession of cross-bedded medium to coarse- grained sandstones and fine conglomerates. The dominant color of the sediments is gray, many of the horizons, however, have a red color. Sedimentary structures include lateral accretion complexes and low-angle, 2D-trough cross bedding. In the 3rd dimension, these structures continue in very persistent cross-bedding with near planar lower and upper bounding surfaces. Bioturbation is present from the lowest exposed horizons to the top of the unit. Horizontal burrows have been ob- served on few bedding planes. Vertical burrows of Skolithos sp. are locally abun- dant in the sandstones of all lithologies, including conglomeratic sandstones. Very scarce Cruziana sp. has also been observed. The upper Dibsiyah is composed of medium to coarse-grained sandstones. Lo- cally, lenses or thin layers of red siltstone to fine-grained sandstone are interca- lated. The dominant sedimentary structure is low-angle, 2D-trough cross bedding of the same type observed in the lower unit. They are laterally very persistent and individual units can be traced over several hundred meters. Herringbone cross stratification is present locally and always associated with the large 2D bedforms. Lateral accretion complexes are also present in this upper part of the Dibsiyah; in- dividual complexes may show foresets up to 2 m high and several centimeters thick. They often show a sigmoidal geometry. Many of them are traceable across entire outcrops. Bioturbation is much more important than in the lower unit. One of the main elements is Skolithos sp. that is present widely scattered within individual hori- zons, somewhat crowded to almost frame-building in some horizons. These pipe rocks, common in many Cambrian and Ordovician siliciclastic successions, are also known as Tigillites. In the upper Dibsiyah, thickness of Skolithos pipe rocks varies between some 10 centimeters to several meters. Simple Skolithos bur- rows are often associated with larger burrows attributed to Bergaueria sp. The
  • 24 H. Al Ajmi et al. almost reef-like horizons of Skolithos and/or Bergaueria are up to 13 meters thick. Most of the internal sedimentary structures have been destroyed by burrow- ing; however, the primary cross-bedding is often faintly visible. The presence of a variety of burrowing organisms and Cruziana sp. in both units testifies to deposition of the entire Dibsiyah in a marine environment. In their majority, the low-angle, 2D through cross-bedded horizons represent tidal chan- nels. The lateral accretion complexes are interpreted as large submarine megarip- ples or dunes typical of meso- to macrotidal environments (Einsele 2000). The lower unit received coarser detritus than the upper unit. This might indicate that the rivers delivering the detritus had higher transport capacity than during de- position of the upper unit or that the coast was close by, in turn indicating a rela- tively low sea level. Towards the upper part of the Dibsiyah, sea-level was rela- tively rising so that after deposition of large submarine dunes, these dunes or megarippels were burrowed by Skolithos and Bergaueria. The depth of burrowing (up to 50 cm) indicates that the animals had abundant time during which no addi- tional sediment was supplied that would have forced the organisms to try to evade. This is in agreement with models that suggest that Skolithos burrows are domi- nantly formed during times of transgression or maximum flooding (e.g., Hamon et al. 2005). Depositional environments were shifting rapidly so that there is a re- peated succession of burrowed and non-burrowed sediments. Sanamah Formation / Qusaiba Shale The Sanamah is a succession of coarse-grained sandstones and conglomerates in its lower part and fine-grained sandstones, siltstones, and some shales in its upper part. The lower Sanamah rests unconformably on the Dibsiyah and fills an erosional relief up to several 10s of meters deep. In many sections outside the actual chan- nels, and beneath the upper Sanamah, there is just a thin veneer (6 10 m) of low- er Sanamah preserved. The basal part of the upper unit was deposited across the post-lower Sanamah topography and has a similar distribution as the sediments of the lower unit. The upper part of the succession is only exposed in the Jibal al Qahr. Although genetically related to the Sanamah Formation, these deposits might represent the subsurface Qusaiba Shale of the Qalibah Formation in this part of Saudi Arabia. In the Jabal Atheer section, the lower Sanamah is 92 m thick. There is no con- tinuous section of the Qusaiba in the study area but in the Jibal al Qahr about 50 m are exposed beneath the unconformity with the Khusayyayn. The lower Sanamah consists of a succession of conglomerates, conglomeratic sandstones, and medium- to coarse grained sandstones. The conglomerates fill large channels and in most cases are the basal fill of the pre-existing topography. They are composed individual lobes, each several 10 of centimeters thick and
  • Advances in understanding the relation between reservoir properties and facies distribution 25 graded, from pebble size at the base to medium or coarse sand in the upper part. Where the basal conglomerate layers had filled up the relief, subsequent layers and channels are locally laterally amalgamating, forming more widespread depos- its (on outcrop scale). Conglomerates are not only present as channel fills but also form part of migrating bars. They mainly show an overall fining-upward or show a lateral decrease in grain size. Above this succession there is a package of gray to yellowish medium to coarse-grained sandstones. In many outcrops, these sand- stones are massive and lack apparent internal structures. Locally, these massive sandstones eroded into the underlying sediment producing overhanging walls. Outside the main valleys, the thin veneer of lower Sanamah consists of channel- ized conglomerates and conglomeratic sandstones with well-developed high- angle, 3D trough cross bedding. Clast- and matrix-supported conglomerates and coarse conglomeratic sand- stones represent the basal channel-fill facies association (Keller et al. 2011). They are interpreted as coarse glacial outwash sediment near melt water outlets. A fa- cies association of massive to cross-bedded sandstones, arranged in clinoforms, fills up the upper part of the valleys. These sediments are interpreted as Gilbert- type deltas prograding from sandur plains into the water-filled valleys during gla- cier retreat. Together with glacial striations, striated clasts, and similar corre- sponding features, these sediments indicate a glacial origin of this part of the Wa- jid Sandstone (Keller et al. 2011). The upper Sanamah starts with an iron-cemented horizon, up to 20 cm which is overlain by some shales and siltstones. Locally sandstones were deposited that in- dicate large-scale slumping. Up section, white fine- to medium-grained sandstones alternate with shales. In its upper part, the upper Sanamah or Qusaiba consists of a succession of light colored fine sandstones, siltstones, and shales. The sediments are thinly bedded and locally show some burrows. Close to the preserved top of the succession, mud cracks have been observed. The basal deposits were laid down rather rapidly, so that the sands were subject to slumping. The lateral variability of the sedimentary successions (Stump and Van der Eem 1996) and the mud cracks indicate that they were probably not de- posited on an open shelf but either in marginal marine environments (deltas) or in a lake setting. Khusayyayn Formation The Khusayyayn Formation (> 52m) is a monotonous succession of medium to coarse-grained sandstones and unconformably rests on older strata. The Khusay- yayn consists of a stacked succession of giant cross-bedded sandstones; individual complexes locally are up to 2 meters high. The foresets are several centimeters thick and are often graded. Grain size mainly decreases from coarse sand to me- dium sand, but locally pebbles have been found in the basal layer of individual
  • 26 H. Al Ajmi et al. foresets. These thick cross-bedded units are associated with herringbone cross stratification and small low-angle, 2D trough-bedded structures. Discrete packages within the succession were found, which seem to occur in all sections. At Jabal Khusayyayn, the succession starts with mainly coarse-grained, large-scale cross- bedded units. This is followed by small-scale bed forms in which medium to coarse sand dominates. Higher up, a massive sandstone unit was found which shows evidence of slumping and dewatering (flame structures). This unit in turn is followed by some 10 meters of fine to coarse-grained sandstones in small-scale bed forms with abundant channels. The uppermost unit again is dominated by large-scal